Antivirus help

I picked up a virus I believe from a game I downloaded it has disabled internet access windows update any restore points etc. I have scanned with kaspersky rescue disk but it didn’t detect anything. I have kadoersky and malware bytes installed but they don’t detect it while the system is running and the bootable usb antivirus didn’t work either. Any other suggestions.

I was thinking of doing a file system integrity check or downloading the windows msrt.

Any suggestions would be appreciated don’t want to have to rebuild my system as there is a lot of historic information I’m fearful of loosing.